A 98-run fourth-wicket partnership between Vijay Zol (43) and Hanuma Vihari (64) helped India to a modest 191 for eight after Sri Lanka had made early inroads to have its opponents reeling at 32 for three.
Sri Lanka's new ball pair of Chamod Pathirana (two for 13 from seven overs) and captain Sanitha de Mel (two for 44) performed strongly, but India were able to post a defendable total on the back of the fourth-wicket stand.
India then dismissed Sri Lanka for 158 in the 46th over after Angelo Jayasinghe had threatened to inspire his side at one stage.
Jayasinghe finished on unbeaten 64 but his effort was not enough to lift Sri Lanka to victory as they struggled to overcome the loss of wickets just when partnerships where threatening to blossom.
For India, Punjab [ Images ] paceman Kamal Passi picked up three for 34.
India: 191 for eight in 50 overs (Hanuma Vihari 64, Vijay Zol 43; Chamod Pathirana 2/13, Lahiru Madushanka 2-28).
Sri Lanka: 158 all out in 45.5 overs (Angelo Jayasinghe 64 not out; Kamal Passi 3/34).